Epidemiologic studies have reported the association between fine particles (aerodynamic diameter ≤ 2.5 μm; PM2.5) and health effects, but the immunological mechanisms are not clear. To investigate the dose and time-dependent role of toll-like receptor (TLR) and Th1/Th2 shift in local and systemic inflammation induced by PM2.5, mice were subjected to intratracheal instillation of 2.5, 5, or 10 mg/kg PM2.5 in this study. After 24 h, 72 h, 7 days, and 14 days, mice were sacrificed to measure TLR2 and TLR4 expressions and Th1/Th2 related cytokines in bronchoalveolar lavage fluid (BALF) and peripheral blood. Histopathological changes in lung were also examined. Inflammatory infiltration and macrophages with engulfed particles were found by lung histopathology after PM2.5 exposure. TLR4 positive cells decreased in BALF but increased in blood at 24 h after the exposure. The low percentage of TLR4 positive cells continued to day 14 in BALF, but recovered at day 7 and decreased further to lower than the control value at day 14 in blood. TLR2 positive cell changed similar to TLR4 in BALF on the dose effects. In BALF at 24 h after the exposure, the Th2 related cytokines IL-5 and IL-10 increased dose-dependently; and in blood, the Th2 related cytokines IL-4, IL-5, and IL-10 also increased. These results suggest that acute exposure of PM2.5 leads to acute inflammatory responses locally and systemically in mice. TLR2 and TLR4 are involved in this process and PM2.5 can drive a Th2-biased immune response.

译文

流行病学研究报道了细颗粒 (空气动力学直径 ≤ 2.5微米; PM2.5) 与健康影响之间的关联,但免疫学机制尚不清楚。为了研究toll样受体 (TLR) 和Th1/Th2转移在PM2.5诱导的局部和全身炎症中的剂量和时间依赖性作用,本研究对小鼠进行气管内滴注2.5、5或10  mg/kg PM2.5。分别于24  h、72  h、7 d、14 d处死小鼠,检测支气管肺泡灌洗液 (BALF) 和外周血中TLR2、TLR4的表达及Th1/Th2相关细胞因子。还检查了肺的组织病理学变化。PM2.5暴露后,通过肺组织病理学发现炎症浸润和巨噬细胞被吞噬的颗粒。暴露后24小时,BALF中TLR4阳性细胞减少,但血液中TLR4阳性细胞增加。BALF中TLR4阳性细胞的低百分比持续到第14天,但在第7天恢复,并进一步下降至低于血液中第14天的对照值。TLR2阳性细胞改变与TLR4在BALF上的剂量效应相似。在暴露后24小时的BALF中,Th2相关细胞因子的IL-5和IL-10呈剂量依赖性增加; 在血液中,Th2相关细胞因子的IL-4,IL-5和IL-10也增加。这些结果表明,PM2.5的急性暴露会导致小鼠局部和全身急性炎症反应。TLR2和TLR4参与了这一过程,PM2.5可以驱动Th2-biased的免疫反应。

+1
+2
100研值 100研值 ¥99课程
检索文献一次
下载文献一次

去下载>

成功解锁2个技能,为你点赞

《SCI写作十大必备语法》
解决你的SCI语法难题!

技能熟练度+1

视频课《玩转文献检索》
让你成为检索达人!

恭喜完成新手挑战

手机微信扫一扫,添加好友领取

免费领《Endnote文献管理工具+教程》

微信扫码, 免费领取

手机登录

获取验证码
登录